(1) Field of the Invention
The invention pertains to a mechanical latching device for threaded connections and to a syringe including such latching device.
(2) Brief Description of the Prior Art
A number of connections utilize threaded components, including nuts and bolts, threaded pipes and couplings, soda bottles and caps, medical connectors, syringes, and the like. Such connections are simple to mate and can be attached and disconnection many times. This simplicity comes with two side effects which are undesirable in certain applications.
First, the presence of angled threads creates the possibility of the connection self-loosening under axial loading--a term referred to as "backdriving." The greater the angle or "pitch" of the threads, the more likely that axial loading will cause backdriving. In some cases, users can add additional components such as lockwashers to prevent backdriving. In other cases, such additions are impractical or too expensive. Hence a need exists to provide backdriving resistance as an integral feature of the threaded connector.
Secondly, very little torque is often required to disassemble the connections. This can be a problem when child-proofing is desired, or when one wants to discourage tampering with an assembly.
The present invention addresses such problems associated with the prior art.
An added advantage of the present invention is that it does not interfere with the ordinary function of threaded connections, and requires both mating sides to incorporate the described changes to operate. Components can be manufactured incorporating the feature, and only when assembled with a mating component also incorporating the feature would the user obtain the desired benefit. Hence a bolt with the features on the threads could still use a regular nut with no noticeable impact; a nut with the feature on its threads could use a regular bolt with no noticeable impact; but a nut and bolt combined, with the mating features described herein, would demonstrate the desired characteristics.